In an eight-year study of more than 50,000 people with bipolar disorder, researchers found that the risk of attempted or completed suicide was reduced significantly when the patients were treated with lithium, compared to an alternative drug called valproate. The study was published online June 9th in The American Journal of Psychiatry.

The study is one of the largest ever to compare suicide risk in patients taking different medications for bipolar disorder, an illness that carries a risk of suicide. It bolsters the conclusions of similar research, including a 2003 study led by BBRF Scientific Council member Frederick K. Goodwin, M.D.

In the new research, led by first author Jie Song, Ph.D., of the Karolinska Institute in Sweden, examined the health records of 51,535 individuals with bipolar disorder in Sweden over a period of eight years, comparing the rate of suicide-related events among those taking either lithium or valproate. The team included Sarah E. Bergen, Ph.D., a 2012 Young Investigator, also at the Karolinska.

The investigators noted 10,648 suicide events during the study period. They found that the rate of attempted or completed suicide dropped by 14 percent when patients were taking lithium compared to when they were off the drug, but they did not see a similar decrease in risk when patients were taking valproate.

Using these figures, the researchers estimate that 12 percent of suicide-related events among the patients could have been avoided if the patients had taken lithium during the entire study period.

“The results suggest that lithium should be considered for patients with bipolar disorder with suspected suicidal intentions, although risk for suicide is only one of the considerations when providing clinical care,” Drs. Jie, Bergen and their colleagues write.